Rock-drill.



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PATBNTBD MAY 14, 1%?.

' Y Nm3# n LEcs'rER Boex DRILL.

YPLIUAIIQK :FILED J8EE 2B, 1966,

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UNITED STATES PATENT OFFICE.

AElYJVlARD liElCll'llElt, UF NEVADA ClTY, CALIFORNIA, ASSIGNOR 0F UNF- HALF T() JAMES C. CAMPBELL, OF NEVADA CTY, GALlFUltN lA.

RGCK-DRILL.

Specification. of Letters Patent.

Patented May 14, 1907.

Application tiled Julie 20, 1906. Serial Nel 322.552.

To will ruumt it may; emmer/'n.-

Be it known that lj Enwann linreirrnn, a citizen ol the United States, residing:r at Nevada City, in the county of Nevada and State of California, have invented new and useful lm rovements in Rock-Drills, of which the ollowing is a specification.

My invention relates to power driven drills and especially to rook drills of the Ingersoll or Sargent type. Its object is to provide a drill of' few parts which will be strong, praetical and durable; which will provide means for adjusting and maintaining in adjustment the cylinder on the shell; which will operate the valve by d ireet pressure from the cylinder in eontradistinetion to the usual exhausted valve motion; and which will have a novel means of balancing the Control valve and permit a ready renewal of the wearing parts Without having:r to discard. the whole valve.

The invention consists ol' the parts and the construction and combination of parts as hereinafter more fully described and Claimed, having reference to the aceompanying drawings, in wliieh- A Figure 1 is a longitudinal sectional view. Fig. 2 is a transverse section. Fig. 3 is a detail view of the valve.

Arepresents vmy eylind er which has its bore turned larger at one end than at the other, and 2 is a double piston turned down in the middle as shown at 3 and having its smaller end litt-ing the smaller end of the cylinder and its larger end fitting the enlarged portion of the bore of the cylinder.

The rear end of the piston engages with the rilile bar 4 in the usual manner, and the front end carries the piston rod 5. The front end of the piston rod is provided with the usual chuck 6. Y

The two ends of the cylinder are made with tapered seats to receive the correspondingly tapered ends of the respective front and rear heads 7-S. The rear head carries the usual ratchet mechanism 9 for imparting, through the medium of the riflie bar 4, an intermittent rotative movement to the drill.

A split bonnet 10 is adapted to lit over the drill rod and the end of the front head 7.

This bonnet l() serves to hold in place and to` ed up against this crimp to eompress it end- VVlSO.

The rear head s is inelosed by a bonnet lil which houses the spring l-'l which abuts against the rear head R and holds the latter to its seat. The front bonnet 10 and the rear bonnet 13 are connected by the usual side rods l5. Sullieient play is provided for the sliding,r movement of the rear bonnet on its seat on the rear end of the Cylinder7 to allow for the absorbance of shook by the springr la.

The cylinder has lateral guide projecting ianges 16 which seat on the shell 17 this shell l? is made with the longitudinally extending; side llanges 1S, and a suitable space is left on each side of the cylinder between the ends oi' the flanges 16 and the flanges 1S for the interposition of the adiusting strips 19. These strips 1) are adapted in the first piace to seat as snu as possible between the flanges 18 and the anges 16. but are transversely slotted as at 20vso that wear takes plane sliims of suitable thickness may be interposed between one or both of the adjusting strips and a corresponding llange 1S. The cylinder is thus held against lateral movement, but is freely slidable lengthwise in the Channels formed by the strips i9, brace flanges 1S and the Clamp stri is 21 and clamp bolts and nuts 22. The feeil of the drill to the work is"d one by the feed screw 22 which is mounted on the shell and engages a feed lnut 22*EL on the eylinder. Y

The use ol? the transveri-relyY slotted ad justing stri is erinits every bit oi" wear between the sliel and Cylinder to be taken up, and thereby prevents side shake of the eylinder on the shell.

The drill piston reeiproeated through the medium of a suitable iluid, suoli as oompressed air admitted alternatelyT to each end of the Cylinder through the ports 23. The admission of the motive fluid is eontrolled by a valve of special design7 located in the valve chest 24.

A double-ended piston 25 operates in the valve ohest and the two piston ends are oonneeted by a ring portion 26, which is adapted to slip over the valve member 27. This valve member has a D-faee adapted to bring one or the other of the inlet ports 23 and the exhaust port 28 into register. The valve is IOO made hollow and is surmounted and held snug to its seat by a ring 2t) whieh rests on the ring 2o and has a snug sliding- [it with the underside ol1 the removable ehest plate $50.

The motive iluid lrom any suitable souree ol' supply is admitted through )ort 3l to the valve ehest and is allowed to eireulate freely on the outside of the valve proper, so that the valve prartieally remains in balanee and the motive Huid whieh is admitted alternately to eaeh end oll the ehest to move the valve, has onlv the weight of the valve and `the lfrietion ot the parte` within the ehest to eontend against. lhatever leak there may be around the top olB the ring 29, linds a ready outlet through the exhaust 2H, By using ring paeking, as this eonstruetion permits, there is practically no leak around the pistons.

The ends ol the ehest are closed by the removable plugs 31.

The lluid to operate the piston valve is admitted alternately to eaeh end of the ehest through one or the other of the parts 3`2f-33 whieh eonneet at eaeh stroke of the piston 2 with a respective live air ehamber at an end of the eylinder A.

Exhaust from the ends of the valve ehest 24 takes place whenever a port Z or 33 is brought into eonnnunieation with the eentral annular passage-way 3; the latter having the exhaust outlets 34.

The operation of the piston valve and oiA the drill piston is as follows: lith a suitable fluid under pressure entering through port 31 and Circulating about the valve, and with the valve moved into position to allow live air to enter the eylinder through one or the other of the ports 23, the drill piston 2 is made to traverse its ehamber until one or thevother of the ports 32e-33, aoeording to which direetion the piston 2 is traveling, is uncovered. Assuming piston 2 to be traveling to the left, the port 32 will be uncovered to put it in` eommunieation with the source of live air supply, while the port 33 will be open to the exhaust through the passage 3 and. ports 34H28. T he live air entering port 32 passes to the left end of the ehest and operates to move the piston valve 25 and allow the exhaust to take plaee from the front end of the eylinder A and to admit live air to the rear end of the eylinder. As soon as the piston 2 has about completed its forward stroke, the port 32 is open to the exhaust and the port 33 is thrown into communication with the live air pressure in the rear end of the eylinder and the piston valve is reversed in the roper manner.

In al valve eonstruetions for rook drills, of whieh l have knowledge, there has been danger ol' leakage around the valve due to wear, which will often result in the valve bein!lr brought to sueh a state ol' balanre that it wiil stiek and rel'use to move. 'lhis dilleulty is entirely obviated in my ronstruetion, sinee the likelihood oll leakage is redueed by the use ol' ring 2U and the hollow valve 2T and the employment ol ring paeking on the piston 25. At the same time my piston valve is worked under the full ell'ertive pressure of live air in the eylinder ,By increasing the diameter oll the eylinder bore at the front end of the eylinder l am enabled to insure a sullieient pressure always being luought on the piston 2, to pull the drill out of the hole; a not infrequent dillieulty heretofore has been the trouble arising from the stieking7 binding or pinehing of the drill in the drill hole. By my eonstruetion ol enlarging the front end ol the ehamber, l make up for the displaeement by the rod 5. By i'naking the two ends of the eylinder and the front and rear heads 7 and. 9 with corresponding tapered seats, it allows the parts to open up in ease the piston bumps the front head, and the outeblowing air will elear the seats of all grit and dirt; thus cleaning themselves and allowing them to seat snug when the piston reverses its movement. With drills using square seats for the eylinder and heads there has always been. dillieulty arising from leaks around the abutting parts.

Having thus described my invention, what I elaim and desire to secure by Letters Patent isei A roek drill having in eombination a eylinder with tapered seats at the ends, a pistonl front and rear heads having corresponding eonieal portions to lit said seats, the rear end of said eylinder having an extension beyond the adjaeent seat, a ehainljiered bonnet inelosing the rear end of the eylinder and reeeiving said extension and having a limited sliding movement relative thereto, a spring within the chamber of said bonnet and abutting against the rear head, a bonnet 'fitting the front end of the eylinder iitting over the drill rod and the end of the front head, and tie rods eonneeting the two bonnets to hohl the heads to their seats on the eylinder, said seats and the eonieal ends of the heads forming loose joints and permitting the heads to give in ease they are struek by the piston, and to reseat themselves.

ln testimony whereof l have hereunto set my hand in presenee of two subscribing witnesses.

EDWARD LE'IVIITER. litnessesz l. C. LINDLEY, R. L. LovELAnY. 

